[PATCH 1/2] spi: apple: Add driver for Apple SPI controller
Mark Kettenis
kettenis at openbsd.org
Sun Jan 16 18:06:12 CET 2022
Add a driver for the SPI controller integrated on Apple SoCs.
This is necessary to support the keyboard on Apple Silicon laopts
since their keyboard uses an Apple-specific HID over SPI protocol.
Signed-off-by: Mark Kettenis <kettenis at openbsd.org>
---
arch/arm/Kconfig | 2 +
drivers/spi/Kconfig | 7 +
drivers/spi/Makefile | 1 +
drivers/spi/apple_spi.c | 283 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 293 insertions(+)
create mode 100644 drivers/spi/apple_spi.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 04b4a20211..fed993a53d 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -937,6 +937,7 @@ config ARCH_APPLE
select DM_MAILBOX
select DM_RESET
select DM_SERIAL
+ select DM_SPI
select DM_USB
select DM_VIDEO
select IOMMU
@@ -946,6 +947,7 @@ config ARCH_APPLE
select POSITION_INDEPENDENT
select POWER_DOMAIN
select REGMAP
+ select SPI
select SYSCON
select SYSRESET
select SYSRESET_WATCHDOG
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index d07e9a28af..0a6a85f9c4 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -50,6 +50,13 @@ config ALTERA_SPI
IP core. Please find details on the "Embedded Peripherals IP
User Guide" of Altera.
+config APPLE_SPI
+ bool "Apple SPI driver"
+ default y if ARCH_APPLE
+ help
+ Enable the Apple SPI driver. This driver can be used to
+ access the SPI flash and keyboard on machines based on Apple SoCs.
+
config ATCSPI200_SPI
bool "Andestech ATCSPI200 SPI driver"
help
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index d2f24bccef..bea746f3e3 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_SPI_MEM) += spi-mem-nodm.o
endif
obj-$(CONFIG_ALTERA_SPI) += altera_spi.o
+obj-$(CONFIG_APPLE_SPI) += apple_spi.o
obj-$(CONFIG_ATH79_SPI) += ath79_spi.o
obj-$(CONFIG_ATMEL_QSPI) += atmel-quadspi.o
obj-$(CONFIG_ATMEL_SPI) += atmel_spi.o
diff --git a/drivers/spi/apple_spi.c b/drivers/spi/apple_spi.c
new file mode 100644
index 0000000000..3ae89dc638
--- /dev/null
+++ b/drivers/spi/apple_spi.c
@@ -0,0 +1,283 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021 Mark Kettenis <kettenis at openbsd.org>
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <clk.h>
+#include <spi.h>
+#include <asm/io.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+
+#define APPLE_SPI_CTRL 0x000
+#define APPLE_SPI_CTRL_RUN BIT(0)
+#define APPLE_SPI_CTRL_TX_RESET BIT(2)
+#define APPLE_SPI_CTRL_RX_RESET BIT(3)
+
+#define APPLE_SPI_CFG 0x004
+#define APPLE_SPI_CFG_CPHA BIT(1)
+#define APPLE_SPI_CFG_CPOL BIT(2)
+#define APPLE_SPI_CFG_MODE GENMASK(6, 5)
+#define APPLE_SPI_CFG_MODE_POLLED 0
+#define APPLE_SPI_CFG_MODE_IRQ 1
+#define APPLE_SPI_CFG_MODE_DMA 2
+#define APPLE_SPI_CFG_IE_RXCOMPLETE BIT(7)
+#define APPLE_SPI_CFG_IE_TXRXTHRESH BIT(8)
+#define APPLE_SPI_CFG_LSB_FIRST BIT(13)
+#define APPLE_SPI_CFG_WORD_SIZE GENMASK(16, 15)
+#define APPLE_SPI_CFG_WORD_SIZE_8B 0
+#define APPLE_SPI_CFG_WORD_SIZE_16B 1
+#define APPLE_SPI_CFG_WORD_SIZE_32B 2
+#define APPLE_SPI_CFG_FIFO_THRESH GENMASK(18, 17)
+#define APPLE_SPI_CFG_FIFO_THRESH_8B 0
+#define APPLE_SPI_CFG_FIFO_THRESH_4B 1
+#define APPLE_SPI_CFG_FIFO_THRESH_1B 2
+#define APPLE_SPI_CFG_IE_TXCOMPLETE BIT(21)
+
+#define APPLE_SPI_STATUS 0x008
+#define APPLE_SPI_STATUS_RXCOMPLETE BIT(0)
+#define APPLE_SPI_STATUS_TXRXTHRESH BIT(1)
+#define APPLE_SPI_STATUS_TXCOMPLETE BIT(2)
+
+#define APPLE_SPI_PIN 0x00c
+#define APPLE_SPI_PIN_KEEP_MOSI BIT(0)
+#define APPLE_SPI_PIN_CS BIT(1)
+
+#define APPLE_SPI_TXDATA 0x010
+#define APPLE_SPI_RXDATA 0x020
+#define APPLE_SPI_CLKDIV 0x030
+#define APPLE_SPI_CLKDIV_MIN 0x002
+#define APPLE_SPI_CLKDIV_MAX 0x7ff
+#define APPLE_SPI_RXCNT 0x034
+#define APPLE_SPI_WORD_DELAY 0x038
+#define APPLE_SPI_TXCNT 0x04c
+
+#define APPLE_SPI_FIFOSTAT 0x10c
+#define APPLE_SPI_FIFOSTAT_TXFULL BIT(4)
+#define APPLE_SPI_FIFOSTAT_LEVEL_TX GENMASK(15, 8)
+#define APPLE_SPI_FIFOSTAT_RXEMPTY BIT(20)
+#define APPLE_SPI_FIFOSTAT_LEVEL_RX GENMASK(31, 24)
+
+#define APPLE_SPI_IE_XFER 0x130
+#define APPLE_SPI_IF_XFER 0x134
+#define APPLE_SPI_XFER_RXCOMPLETE BIT(0)
+#define APPLE_SPI_XFER_TXCOMPLETE BIT(1)
+
+#define APPLE_SPI_IE_FIFO 0x138
+#define APPLE_SPI_IF_FIFO 0x13c
+#define APPLE_SPI_FIFO_RXTHRESH BIT(4)
+#define APPLE_SPI_FIFO_TXTHRESH BIT(5)
+#define APPLE_SPI_FIFO_RXFULL BIT(8)
+#define APPLE_SPI_FIFO_TXEMPTY BIT(9)
+#define APPLE_SPI_FIFO_RXUNDERRUN BIT(16)
+#define APPLE_SPI_FIFO_TXOVERFLOW BIT(17)
+
+#define APPLE_SPI_SHIFTCFG 0x150
+#define APPLE_SPI_SHIFTCFG_CLK_ENABLE BIT(0)
+#define APPLE_SPI_SHIFTCFG_CS_ENABLE BIT(1)
+#define APPLE_SPI_SHIFTCFG_AND_CLK_DATA BIT(8)
+#define APPLE_SPI_SHIFTCFG_CS_AS_DATA BIT(9)
+#define APPLE_SPI_SHIFTCFG_TX_ENABLE BIT(10)
+#define APPLE_SPI_SHIFTCFG_RX_ENABLE BIT(11)
+#define APPLE_SPI_SHIFTCFG_BITS GENMASK(21, 16)
+#define APPLE_SPI_SHIFTCFG_OVERRIDE_CS BIT(24)
+
+#define APPLE_SPI_PINCFG 0x154
+#define APPLE_SPI_PINCFG_KEEP_CLK BIT(0)
+#define APPLE_SPI_PINCFG_KEEP_CS BIT(1)
+#define APPLE_SPI_PINCFG_KEEP_MOSI BIT(2)
+#define APPLE_SPI_PINCFG_CLK_IDLE_VAL BIT(8)
+#define APPLE_SPI_PINCFG_CS_IDLE_VAL BIT(9)
+#define APPLE_SPI_PINCFG_MOSI_IDLE_VAL BIT(10)
+
+#define APPLE_SPI_DELAY_PRE 0x160
+#define APPLE_SPI_DELAY_POST 0x168
+#define APPLE_SPI_DELAY_ENABLE BIT(0)
+#define APPLE_SPI_DELAY_NO_INTERBYTE BIT(1)
+#define APPLE_SPI_DELAY_SET_SCK BIT(4)
+#define APPLE_SPI_DELAY_SET_MOSI BIT(6)
+#define APPLE_SPI_DELAY_SCK_VAL BIT(8)
+#define APPLE_SPI_DELAY_MOSI_VAL BIT(12)
+
+#define APPLE_SPI_FIFO_DEPTH 16
+
+#define APPLE_SPI_TIMEOUT_MS 200
+
+struct apple_spi_priv {
+ void *base;
+ u32 clkfreq;
+};
+
+static void apple_spi_set_cs(struct apple_spi_priv *priv, int on)
+{
+ writel(on ? 0 : APPLE_SPI_PIN_CS, priv->base + APPLE_SPI_PIN);
+}
+
+static void apple_spi_tx(struct apple_spi_priv *priv, uint *len,
+ const void **dout)
+{
+ const u8 *out = *dout;
+ u32 data, fifostat;
+ uint count;
+
+ fifostat = readl(priv->base + APPLE_SPI_FIFOSTAT);
+ count = APPLE_SPI_FIFO_DEPTH -
+ FIELD_GET(APPLE_SPI_FIFOSTAT_LEVEL_TX, fifostat);
+ while (*len > 0 && count > 0) {
+ data = out ? *out++ : 0;
+ writel(data, priv->base + APPLE_SPI_TXDATA);
+ (*len)--;
+ count--;
+ }
+
+ *dout = out;
+}
+
+static void apple_spi_rx(struct apple_spi_priv *priv, uint *len,
+ void **din)
+{
+ u8 *in = *din;
+ u32 data, fifostat;
+ uint count;
+
+ fifostat = readl(priv->base + APPLE_SPI_FIFOSTAT);
+ count = FIELD_GET(APPLE_SPI_FIFOSTAT_LEVEL_RX, fifostat);
+ while (*len > 0 && count > 0) {
+ data = readl(priv->base + APPLE_SPI_RXDATA);
+ if (in)
+ *in++ = data;
+ (*len)--;
+ count--;
+ }
+
+ *din = in;
+}
+
+static int apple_spi_xfer(struct udevice *dev, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct apple_spi_priv *priv = dev_get_priv(dev->parent);
+ unsigned long start = get_timer(0);
+ uint txlen, rxlen;
+ int ret = 0;
+
+ if ((bitlen % 8) != 0)
+ return -EINVAL;
+ txlen = rxlen = bitlen / 8;
+
+ if (flags & SPI_XFER_BEGIN)
+ apple_spi_set_cs(priv, 1);
+
+ if (txlen > 0) {
+ /* Reset FIFOs */
+ writel(APPLE_SPI_CTRL_RX_RESET | APPLE_SPI_CTRL_TX_RESET,
+ priv->base + APPLE_SPI_CTRL);
+
+ /* Set the transfer length */
+ writel(txlen, priv->base + APPLE_SPI_TXCNT);
+ writel(rxlen, priv->base + APPLE_SPI_RXCNT);
+
+ /* Prime transmit FIFO */
+ apple_spi_tx(priv, &txlen, &dout);
+
+ /* Start transfer */
+ writel(APPLE_SPI_CTRL_RUN, priv->base + APPLE_SPI_CTRL);
+
+ while ((txlen > 0 || rxlen > 0)) {
+ apple_spi_rx(priv, &rxlen, &din);
+ apple_spi_tx(priv, &txlen, &dout);
+
+ if (get_timer(start) > APPLE_SPI_TIMEOUT_MS) {
+ ret = -ETIMEDOUT;
+ break;
+ }
+ }
+
+ /* Stop transfer. */
+ writel(0, priv->base + APPLE_SPI_CTRL);
+ }
+
+ if (flags & SPI_XFER_END)
+ apple_spi_set_cs(priv, 0);
+
+ return ret;
+}
+
+static int apple_spi_set_speed(struct udevice *dev, uint speed)
+{
+ struct apple_spi_priv *priv = dev_get_priv(dev);
+ u32 div;
+
+ div = DIV_ROUND_UP(priv->clkfreq, speed);
+ if (div < APPLE_SPI_CLKDIV_MIN)
+ div = APPLE_SPI_CLKDIV_MIN;
+ if (div > APPLE_SPI_CLKDIV_MAX)
+ div = APPLE_SPI_CLKDIV_MAX;
+
+ writel(div, priv->base + APPLE_SPI_CLKDIV);
+
+ return 0;
+}
+
+static int apple_spi_set_mode(struct udevice *bus, uint mode)
+{
+ return 0;
+}
+
+struct dm_spi_ops apple_spi_ops = {
+ .xfer = apple_spi_xfer,
+ .set_speed = apple_spi_set_speed,
+ .set_mode = apple_spi_set_mode,
+};
+
+static int apple_spi_probe(struct udevice *dev)
+{
+ struct apple_spi_priv *priv = dev_get_priv(dev);
+ struct clk clkdev;
+ int ret;
+
+ priv->base = dev_read_addr_ptr(dev);
+ if (!priv->base)
+ return -EINVAL;
+
+ ret = clk_get_by_index(dev, 0, &clkdev);
+ if (ret)
+ return ret;
+ priv->clkfreq = clk_get_rate(&clkdev);
+
+ /* Set CS high (inactive) and disable override and auto-CS */
+ writel(APPLE_SPI_PIN_CS, priv->base + APPLE_SPI_PIN);
+ writel(readl(priv->base + APPLE_SPI_SHIFTCFG) & ~APPLE_SPI_SHIFTCFG_OVERRIDE_CS,
+ priv->base + APPLE_SPI_SHIFTCFG);
+ writel((readl(priv->base + APPLE_SPI_PINCFG) & ~APPLE_SPI_PINCFG_CS_IDLE_VAL) |
+ APPLE_SPI_PINCFG_KEEP_CS, priv->base + APPLE_SPI_PINCFG);
+
+ /* Reset FIFOs */
+ writel(APPLE_SPI_CTRL_RX_RESET | APPLE_SPI_CTRL_TX_RESET,
+ priv->base + APPLE_SPI_CTRL);
+
+ /* Configure defaults */
+ writel(FIELD_PREP(APPLE_SPI_CFG_MODE, APPLE_SPI_CFG_MODE_IRQ) |
+ FIELD_PREP(APPLE_SPI_CFG_WORD_SIZE, APPLE_SPI_CFG_WORD_SIZE_8B) |
+ FIELD_PREP(APPLE_SPI_CFG_FIFO_THRESH, APPLE_SPI_CFG_FIFO_THRESH_8B),
+ priv->base + APPLE_SPI_CFG);
+
+ return 0;
+}
+
+static const struct udevice_id apple_spi_of_match[] = {
+ { .compatible = "apple,spi" },
+ { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(apple_spi) = {
+ .name = "apple_spi",
+ .id = UCLASS_SPI,
+ .of_match = apple_spi_of_match,
+ .probe = apple_spi_probe,
+ .priv_auto = sizeof(struct apple_spi_priv),
+ .ops = &apple_spi_ops,
+};
--
2.34.1
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